.yhxqda{
    width: 100vw;
    height: 100vh;
    background-color: #2b2b2b;
}
.yhxqbox{
    width: 90%;
    height: 500px;
    background: #fff;
    margin: 0 auto;
    margin-top: 20px;
    p{
        line-height: 40px;
    }
}